[PATCH RT] locking/rtmutex: don't drop the wait_lock twice

[Sebastian Andrzej Siewior]

Since the futex rework, __rt_mutex_start_proxy_lock() does no longer
acquire the wait_lock so it must not drop it. Otherwise the lock is not
only unlocked twice but also the preemption counter is underflown.

Cc: rt-sta...@vger.kernel.org
Reported-by: Gusenleitner Klaus <g...@keba.com>
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
---
 kernel/locking/rtmutex.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index f03876322d4a..79f49d73e4d0 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -2281,7 +2281,6 @@ int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
        raw_spin_lock(&task->pi_lock);
        if (task->pi_blocked_on) {
                raw_spin_unlock(&task->pi_lock);
-               raw_spin_unlock_irq(&lock->wait_lock);
                return -EAGAIN;
        }
        task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
-- 
2.14.1